A number of motionless mixer types exist, such as Multiflux, helical and others. These mixer types, for the most part, implement the same general principle to mix fluids together in a fluid dispenser. In these mixers, fluids are mixed together by dividing and recombining the fluids in an overlapping manner. This action is achieved by forcing the fluid over a series of mixing baffles of alternating geometry. Such division and recombination causes the layers of the fluids being mixed to thin and eventually diffuse past one another. This mixing process has proven to be very effective, especially with high viscosity fluids. One exemplary type of static mixer includes a series of alternating mixing baffles, of varying geometries, such as right-handed and left-handed mixing baffles disposed in a conduit to perform the continuous division and recombination.
These types of mixers are generally effective in mixing together most of the mass fluid flow, but a high number of mixing baffles must be provided to thoroughly mix the fluids, thereby increasing the overall length of the mixer. This additional length is undesirable because the fluid dispenser with a long static mixer may not be compact enough for certain dispensing operations. In order to shorten the static mixer, newer mixing baffles have been developed that include a higher number of intersecting blades or plates that form a lattice for simultaneously dividing the mass fluid flow into many more than two portions. These mixing baffles mix the mass fluid flow more rapidly and therefore enable the static mixer to be shortened considerably.
However, mixing baffles with a high number of intersecting blades are more difficult to manufacture. For example, U.S. Pat. No. 4,220,416 to Brauner et al. describes a mixing baffle molded as two V-shaped comb-like portions molded separately and intermeshed with each other before insertion into the conduit of the static mixer. The high number of intersections between blades in these mixing baffles defines a significant number of undercuts that are not moldable without specialty molding equipment or are impossible to mold. Even if these mixing baffles are molded, each mixing baffle must be molded separately rather than being molded as part of a unitary baffle stack, which is common in the static mixer field. As a result, the manufacture and assembly of each separate mixing baffle and the conduit to form a static mixer is complex, costly, and time-consuming.
Additionally, each manufactured mixing baffle must conform to a tight tolerance to properly fit within the conduit while providing a frictional fit with the conduit. Without molding each mixing baffle as a unitary baffle stack, tolerance inconsistencies between mixing baffles can make assembly of the various mixing baffles into the conduit difficult, if not impossible. Thus, it would be desirable to address some of the problems associated with manufacturing static mixers including these mixing baffles with a high number of undercuts.